An article in Knee Surgery, Sports Traumatology, Arthroscopy (2005, Vol. 13, pp. 273-279), considered arthroscopic meniscal repair with an absorbable screw. Results showed that for tears greater than 25 millimeters, 15 of 17 (88%) repairs were successful while for shorter tears, 23 of 31 (74%) repairs were successful. (a) Is there evidence that the success rate is greater for longer tears? Use alpha=0.05 . What is the P -value?
(b) Calculate a one-sided 95% confidence bound on the difference in proportions that can be used to answer the question in part (a).
Solution format:
(a) There (is or is not) evidence that the success rate is greater for longer tears. The P -value is Round your answer to four decimal places (e. g. 98.7654).
(b) The one-sided 95% confidence bound is ? <=p1-p2 . Round your answer to three decimal places (e. g. 98.765).